The invention relates to a semiconductor device for the summation of a number of weighted input signals, comprising a semiconductor body with a surface region of a first conductivity type adjoining a surface, which surface is provided with an electrode configuration which is insulated from the surface region and has an electrically floating gate and, for the supply of the signals to be summed, with a number of input electrodes which are electrically insulated from the surface of the semiconductor body and from the floating gate and which are capacitively coupled to the floating gate. The device may form, for example, a neural network in which electrical signals are weighted in synapses and in which the sum of the weighted input signals is convened into one or several output signals Y.sub.i by means of a non-linear function by neurons. The signals Y.sub.i themselves may again form input signals for neurons of a next layer.
A semiconductor device of the kind described in the opening paragraph is known inter alia from the article: "A Functional MOS Transistor Featuring Gate-Level Weighted Sum and Threshold Operations" by T. Shibata and T. Ohmi, published in IEEE Transactions on Electron Devices, vol. 39, no. 6, Jun. 1992, pp. 1444-1455. An MOS transistor with floating gate is described therein with a number of input gates which are capacitively coupled to the floating gate. The input signals are supplied to the input electrodes in weighted form, the potential of the floating gate being determined by the sum of the signals supplied to the input electrodes. A measurement of the source/drain current dependent on the potential of the floating gate can yield a parameter which is representative of the sum of the weighted input signals. In this device, additional means are to be provided for the storage of the weight factors and for weighting of the input signals, which may result in a very complicated circuit. The device is also strongly temperature-dependent, in particular owing to the temperature dependence of the mobility in the transistor channel.